Inverting apparatus for stacked sheet material



P. FONTANA 3,063,575

Nov. 13, 1962' INVERTING APPARATUS FOR STACKED SHEET MATERIAL Filed Oct.14, 1959 2 Sheets-Sheet l a l II I' l ll 7 7 8 7 0 U 6 (8 E B J 7 00 c//7 Q j P 7 00 f 7 2Q 7 ,/0 5 L. W1. K 4 m PCiOIO FO'NTANA INVENTOR.

AGENT Nov. 13, 1962 P. FONTANA 3,063,575

INVERTING APPARATUS FOR STACKED SHEET MATERIAL 2 Sheets-Sheet 2 FiledOct. 14, 1959 /4 kW 5 I PC1010 FON TANA INVENTOR.

BY KM AGENT United States Patent M 3,063,575 INVERTING APPARATUS FQREiTACKEi SHEET MATERIAL Paolo Fontana, Via F. Brioschi 62, Milan, ItalyFiled Oct. 14, 1959, Ser. No. 846,317 Claims priority, application ItalyOct. 15, 1958 1 Claim. (Cl. 2141) This invention relates to an invertingapparatus capable of rapidly overturning and setting in order piles orskids of stacked sheets of, for instance, printing paper.

The difiiculties of inverting piles or stacks of sheets delivered toprinting machine beds for printing the sheets on their reverse side areknown.

This inverting operation may be carried out manually or by means ofmechanical devices which generally impart to the stack a rotation ofabout at least 180 about a horizontal axis, or a movement or" only oneor two degrees of freedom.

The main drawbacks of the manual method are obvious; whereas in the caseof the known inverting machines, their great complexity, high cost, andencumbering nature constitute their disadvantages.

An object of the invention is to eliminate the abovementioned drawbacksand to provide a device which allows the carrying out in a very shorttime period, and with excellent results, of the inversion of piles ofsheets of any size and weight, and which returns the same stack ofsheets to the same bed of the machine, perfectly centered and alignedwith respect to the other carrying beds.

Another object of this invention is to effect a complete inversion ofthe piles of printing paper with such a composite rotation that therotation in a vertical plane occurs only through an angle of 90 andafter the complete inversion, the pile is again positioned in thestarting position.

These and other objects are attained by a machine, according to theinvention, which is characterized in that it comprises a platform membercarrying the pile of sheets; the platform member being mounted so as tobe able to rotate both about a first axis perpendicular to the plane ofthe platform and about a second axis parallel to that plane, in order toallow a complete turnover of the piles by means of a first rotation ofthe platform member through approximately a quarter of a revolution inone direction about said second axis, a second rotation of about half arevolution about said first axis and a third rotation of approximately aquarter of a revolution again about said second axis, but in oppositedirection to said first rotation, so as to replace the pile completelyinverted in the same starting place.

This invention will now be more fully described with reference to apreferred embodiment shown by way of example in the accompanying drawingin which:

FIG. 1 is a perspective view of the machine according to the invention;

FIG. 2 is a lateral-elevational view of the said machine, in thestarting or loading position;

FIG. 3 is a plan view of the machine illustrated in FIG. 2;

FIG. 4 is a lateral-elevational view of the machine in the invertedstage of the stack;

FIG. 5 is a diagrammatic view of a device for the self-centering of theoperated complex;

FIG. 6 is a cross-sectional view taken along line AA of FIG. 7, of alocking device;

FIG. 7 is an elevational view taken along line BB of FIG. 6;

FIG. 8 is an elevational view illustrating a modification of the drivingmeans for the platforms.

With reference to the drawings, the machine accord- 3,63,575. PatentedNov. 13, 1962 ing to the invention comprises clamping means,particularly self-centering jaws, constituted by slidable cantileverarms 1, 1', which are supported by a rotating member 2, in the form of aplatform of convenient size, which platform is provided with meansallowing it to rotate about an axis perpendicular to the plane of theplatform 2, as will be described below.

A self-centering device is associated with the clamping device and is soarranged that the resistant forces are minimum. Particularly, totransmit rotational movement to the platform 2 about this axis, which isperpendicular to the platform, it is possible to use the mechanical combination represented diagrammatically in the drawing; the drive means ismainly constituted by a rod 19, driven in any known manner, for instanceby means of an electrical motor 14, with double reduction through aV-belt trans mission 15, 16 and gears 17, 18, the rod 19 is oppositelythreaded at the ends thereof and engages at said ends, in internallythreaded bores of screw-nut members 20. These screw-nut members are anintegral part of elements which drive the cantilever arms 1, 1, andwhich are advan tageously made in the form of two transverse bars 21,21, one of which entrains the lower cantilever arm 1 and the other ofwhich entrains the upper cantilever arms 1. The rotation of the threadedrod 19 causes the approaching and spreading of the jaws 1, 1' in aconvenient way and consequently the centering of the stack 4 of sheetsinserted between the jaws. It will be understood that when the threadedrod 19 is locked, the rotation of gear 17 (see FIG. 5) will cause therotation of platform about the axis 5 thereof.

In the illustrated apparatus the self-centering device proper isarranged conveniently within the interior of the rotating platform 2,while the driving means, particularly the electrical motor and thereduction gear transmission, are conveniently arranged partially in thehousing 7 and partially in the platform itself, the transmission shaft16' passing through the hollow pin 5. Pin 5 is rigidly secured to atilting platform 3 and permits the rotation of platform 2 about itsaxis.

Limit switches 6 stop the drive motor when the jaws have reached theirmaximum spread, while an excessive compression of the center pile may beavoided by the provision of known compression sensitive means adapted tostop the motor when a desired pressure on the pile is reached. The sameresult may be obtained by a maximum-current play relay inserted in thesupply circuit of the electric motor.

The cantilever arms 1, 1 constituting the clamping member of themachine, project through slots 8, provided within the rotating platform2, and are conveniently guided and supported in the platform 2 by thethreaded rod 19 and transverse bars 21. The rotating member 2 issupported by a tilting platform 3, with the aid of supporting meansadapted to allow a rotation of the carrying platform 2 together with thestacked pile in a dynamically and statically safe and stable manner.

The above mentioned means comprise the hollow pin 5, a thrust bearing,not shown and finally a locking device indicated at 9 and representedmore particularly in FIGS. 6 and 7.

This locking and stiffening device serves to rigidly but removablyconnect the two platforms in convenient mutual positions and to providea greater stability to the system. In the embodiment shown in FIGS. 6and 7 this locking device comprises a sliding cylindrical member 22,which is maintained in the locking position by means of a spring, and isprovided with a control lever 24. Said sliding cylindrical member isadapted to engage in a slot 25 of suitable shape, thereby locking theplatform 2 on the tilting platform 3, and is maintained in the lockingposition by means of the spring 23; the lever 24 is guided within acurved slot 26 which allows a free action of the spring 23 on thelocking member 22 in the locking position thereof and prevents the.action of the spring when the connection of the two platforms has to bereleased.

The bearing supporting the rotating platform (eg. a thrust hearing) maybe of any known type and should be adapted to support heavy loads. Itmay conveniently be a ball bearing whose balls distribute the load ontoother balls, said balls being arranged and guided in a conventionalmanner.

The rotation of the carrying platform 2 about the axis of the hollow pin5, which rotation occurs with the platform in a horizontal position soas to allow the complete turnover of the stacked pile by means of atilting rotation of only 90, may be carried out by means of the abovedescribed electrical motor 14, and gears 16, 17, 18, when the threadedrod- 19 is locked. It is however obvious that this rotation may becarried out by means of other convenient devices and if desired alsomanually, since this rotation takes place in a horizontal plane and theresisting friction forces are low.

The tilting platform 3, supports the carrying platform 2, which issuperposed and pivoted thereon, is in turn rotatably supported on arigid base 40, by pins 12, so as to be able to rotate about thehorizontal axis of the pins 12, through an angle of approximately 90.

The pins 12 are fixed in supporting brackets 13, fixed on the base 40.

The rotation through about 90, which is a main feature of the lowerplatform 3, allows an easy squaring and alignment of the paper pile andsimplifies the following turnover movement, the squaring and alignmentbeing carried out when the superposed platforms are in an horizontalposition, as shown in FIG. 4.

The tilting or swinging movement of the platform 3 may be obtained bymeans of any convenient driving device, but in the embodiment shown, thetilting of the platform 3 is obtained via sprocket chain 11, engaging asprocket driven through a transmission by a motor not shown in thedrawing.

Limit switches 37, of any known kind, may automatically stop the actionof the driving source, in order to prevent shocks when the platformreaches its extreme position.

Conveniently the limit switches may be controlled by the movement of thetilting platform itself.

According to the invention, the mutual position of the rotation axis ofplatforms 2 and 3 are so arranged as to allow the movable complex toautomatically return by gravity action, from the horizontal position inthe starting or loading position of the movable complex, braking meansbeing provided in the movable complex in order to damp the returnmovement of said movable complex.

In the modification shown in FIG. 8, the tilting of the platforms 2, 3is carried out by means of a hydraulic or pneumatic jack comprising apower cylinder 30 at the bottom part of which is hinged at 31 at thebase 40 of the machine, whereas the piston rod 32 of the jack is hingedat its free end 33 on the tilting platform 3 of the turnover machine ata location situated below the pivot 12, when the platform 3 is in itsvertical position. In this way the extension of jack 30 will cause theplatforms 2, 3 to rotate from the vertical position thereof towards thehorizontal position thereof. It will also be understood that, whenreturning by gravity action from the horizontal position in the verticalposition, the jack 30 will damp the lowering of the plates so that noauxiliary braking means will be necessary for this purpose.

From the above description the functioning of the inventive machine willbe obvious. The normal operating cycle may be summarized as follows,pointing out only the main features of the operation:

(a) The loading of the paper pile 4, with platforms 2 and 3-, in avertical position;

(b) Self-centering of the paper pile, by actuation of the jaws 1, 1 soas to suificiently but not excessively clamp the stack of printingpaper;

(0) A rotation through an angle of about of the group constituted of thetwo platforms 2 and 3, about the axis of the pins 12, until the twoplatforms reach a horizontal position;

(d) A rotation through an angle of about of the upper platform 2 aboutthe pin 5;

(e) A rotation of the group formed of the two platforms 2 and 3, againabout the pins 12, but in the opposite direction, thereby returning theoverturned pile in its initial position;

(1) The unloading of the pile 4, which is now completely overturned.

A switchboard 38 is provided to facilitate the control of the operationby means of convenient push buttons. It is obvious that the operationstages may be sequentially operated in an automatic way by knownelectromagnetic means.

It is obvious that the invention may obtain various modifications whichwill be evident to those skilled in the art, which all lie within thescope of the invention defined by the following claim.

I claim:

An inverting apparatus for stacked sheet material com prising a base; afirst platform member pivoted to said base intermediate two oppositeextremities of said first platform member for angular motion about afixed first axis; a second platform member rotatably journaled to saidfirst platform for rotation in a plane generally parallel thereto abouta second axis perpendicular to said first axis; clamping means on saidsecond platform member for seizing stacks of sheet material, saidclamping means including at least two clamping arms extending generallyperpendicularly from said second platform member and slidably mountedthereon, a lead screw on said second platform member having a pair ofoppositely threaded extremities each respectively engaging one of saidarms, a drive shaft journaled in said first platform and extendinggenerally perpendicularly therefrom for rotation about said second axis,said lead screw and said drive shaft being provided with matingbevel-gear means, and motor means on said first platform member forrotating said drive shaft, thereby reciprocating said arms toward andaway from each other; and actuating means for displacing said firstplatform member about said first axis, said bevel-gear means comprisinga first bevel gear on said shaft and a second bevel gear on said leadscrew intermediate said threaded extremities in mesh with said firstbevel gear in all angualr positions of said second platform member.

References (Iited in the file of this patent UNITED STATES PATENTS2,318,791 Mueller May 11, 1943 2,469,644 Harrison May 10, 1949.2,718,320 Nelson et a1. Sept. 20, 1955 2,772,766 Kellam Dec. 4, 19562,862,629 Aberle Dec. 2, 1958

